[AC Question]

I am a new Android user so be patient with me.
The phone is the Motorola Moto E (2nd) with Android 5.0.2.
The file manager I use is ES File Explorer and for the music I use Rocket Player.

Today I started wondering if I can add a thumbnail to the folders that hold the music I listen to. I first tried to do that with Rocket Player, but it allows me to "Manage Art" only in the Albums tab and not in the Folders tab which is what interests me.
Then I decided to try ES File Explorer to do this, but when I select a folder, the only relevant option I see is "Associate app" which, unfortunately, is not what I want.

Is there another app that allows this function. I appreciate any advice or suggestion you offer. Thanks.

[B. Diddy]

Welcome to Android Central! Are you trying to add album art to your music files? Or do you want to change the folder icon into a thumbnail instead?